Industrial robots of this type with parallel kinematics are used to move, position and/or process an object in space. They include Delta robots, for example. These are equipped with at least two control arms as actuating units. Each control arm has an upper and a lower arm section, which are connected to one another in a moveable manner. Each of the upper arm sections is driven by a drive, for example, a motor-gear unit. The drives are arranged on the robot base. The movement of the upper arm sections is transferred via the lower arm sections to a carrier element. Each lower arm section has two parallel rods or struts running in the longitudinal direction of the arm section, which are moveably connected at their one end to the associated upper arm section and at their other end are moveably connected to the carrier element. For example, a gripper for picking up an object or a tool for processing an object can be arranged on the carrier element. To this end the carrier element is equipped with a receptacle for a gripper or a tool. The gripper or the tool arranged on the carrier element can be moved in several dimensions in a targeted manner by means of the movement of the driven upper arm sections coordinated with one another. The control arms effect a spatial parallelogram guidance of the carrier element. The parallel kinematics resulting therefrom render possible a rapid and precise movement of the carrier element and of the gripper or tool arranged thereon. A torque and/or a force can be transferred to the gripper or the tool by means of an additional transfer device arranged on the robot base. If the industrial robot is equipped with three control arms, the transfer device is referred to as a fourth axis.
In addition to Delta robots, industrial robots with parallel kinematics also include cable robots. Cable robots are equipped with cables as actuating units. Each cable is connected by its one end to a drive. The drives are embodied as rotation or linear drives which give the free length of the cables by winding and unwinding on a shaft connected to a cable end or by advancing or retracting a push rod connected to a cable end. At their end facing away from the drive, the cables are connected to a carrier element for a gripper or a tool. It must be ensured thereby that the cables are tensioned. The gripper or the tool arranged on the carrier element can be moved in several dimensions in a targeted manner by means of the movement of the drives coordinated with one another.
A gripper arranged on the carrier element or a tool arranged on the carrier element is actuated via a pneumatic, hydraulic or electric drive. For this purpose, the gripper or the tool is connected to the robot base via hydraulic, pneumatic, electric or optical supply lines, on which robot base the drive or a part of the drive for the actuation of the gripper or the tool is arranged. The supply lines are used for the transport of compressed air, a pressure liquid, electric current or light. Light can be necessary, for example, for a sensor arranged on the gripper or on the tool. The supply lines thereby connect the robot base to the carrier element freely and without guidance or they are guided along the actuating units or along the transfer device.
An industrial robot of this type with actuating units in the form of control arms is known, for example, from EP 250 470 A1.
Since industrial robots of this type are also used in the field of food production and food processing, they must satisfy high requirements in terms of hygiene, the harmlessness of materials from which the components of the industrial robot are made and the compatibility with the objects to be moved or processed. In particular the components of the industrial robot coming into contact with the objects must be regularly cleaned. It is important thereby that a cleaning fluid used for cleaning can flow around the components of the industrial robot. The cleaning of the supply lines in particularly has thereby proven to be disadvantageous. If they are guided along the actuating units or the transfer device, dirt can collect in the gaps between the supply lines and the actuating units or the transfer device, which is difficult to access for a cleaning. Furthermore, special demands are made on the supply lines, in particular on their coating or covering with regard to its harmlessness with respect to the objects processed with the industrial robot. Finally, there is a risk of the supply lines being damaged during cleaning.